I enjoy a lot of different bands and artists. This kind of goes along with the question of "What style fiddle do you play" because each of these bands and artist have been a big influence on my playing one way or another. Some of my favorites are:

Dervish
Banish Misfortune
Kevin Burk
Alasdair Fraser
John Whelen
Altan
John Hartford
Falderal String Band
Allen Street String Band
Prairie Land String Band
Sweet Song String Band
Boru's Ghost
Calliope House
Altan
DeDannan
and many many more.